Could Switching Water Save Your Memory?

Something as ordinary as your tap water could influence your risk of developing dementia. While most people think about water in terms of taste or plumbing issues, scientists are now exploring how the minerals in your water could play a surprising role in preserving your brain health.

Key Takeaways

• Hard Water May Protect the Brain: Individuals living in hard water areas showed a lower risk of Alzheimer's and vascular dementia compared to those in soft water regions.
• Calcium and Magnesium Are Crucial for Brain Health: These minerals support neuron communication and memory processes, and deficiencies are linked to cognitive decline.
• Widespread Mineral Deficiencies Exist: Most adults, especially seniors, do not meet daily recommended intake levels of calcium and magnesium—making supplementation a smart move regardless of local water hardness.

The Shocking Dementia Link Hiding in Your Water Supply

A new study has uncovered a potential link between water hardness and dementia risk, challenging long-held assumptions and raising fascinating questions about how even the most mundane aspects of daily life might affect our long-term cognitive function.

There’s a lot to find annoying about hard water. Soap scum on dishes, crusty showerheads, clogged pipes, appliances that give up the ghost far sooner than they should. But hard water does have its plus side.

It reduces the risk of bone fractures, heart disease and stomach cancer, and might even protect against obesity. And in a first-of-its-kind study, hard water was shown to lower the risk of Alzheimer’s disease and vascular dementia.

Mighty Minerals: Why Hard Water Might Be the Brain’s Best Friend

The amount of calcium and magnesium dissolved in water as it passes through different types of soil and rock determines its hardness. Soft water is defined as having 0–60 mg/L of calcium carbonate, moderately hard as 61-120 mg/L, and hard as 121-180 mg/L.

In the U.S. only around 15% of the population live in soft water areas - the Pacific Northwest, parts of the Southeast, the Gulf States and New England.

As well as calcium and magnesium, other minerals found at higher levels in hard water, such as sodium, iron, potassium, zinc, and manganese, are needed for good health, so it comes as no surprise that the more minerals in the water, the healthier we’ll be.

In fact, water with a low mineral content is a potential risk factor for various health conditions, including cancer, hypertension, diabetes, and obesity. ¹ Still, no group had investigated whether water hardness is linked to dementia, so a team from China dedicated themselves to the task.

Soft Water Shrinks The Brain

The scientists made use of the UK Biobank, which contains a huge amount of data on half a million people who volunteered to provide medical, genetic and lifestyle information.

To estimate water hardness and whether it’s linked to the incidence of dementia, they looked at the home addresses of nearly 400,000 middle-aged and older men and women, none of whom were affected by dementia when water samples were collected and measured in 2005.

Seventeen years later, however, 2,389 had received a diagnosis of Alzheimer’s and another 1,278 for vascular dementia.

When analyzing the data, liquid consumption and multiple factors that influence the incidence of dementia were adjusted for. A subgroup of more than 32,000 also had brain scans to look for physical changes.

Comparing those living in soft and moderately hard water areas to those living in hard water areas, the key findings showed they had a:

• 13% elevated risk of Alzheimer’s disease
• 24% elevated risk of vascular dementia
• Atrophy in 24 brain structures, making them more vulnerable to neurodegenerative diseases ²

Living in hard water areas is brain protective, according to their findings but experts were critical.”

Dr. Tom Russ, director of the Alzheimer Scotland Dementia Research Centre, believes water hardness may be part of the dementia puzzle but “most people shouldn’t be too worried about the effect that tap water might have. If it has any effect, it’ll be very small.”⁵

Regardless of whether this study can be relied upon or not, the fact is that both calcium and magnesium are crucial for brain cell communication and healthy cognition. Deficiencies disrupt brain signaling and memory processes.

Calcium and Magnesium Deficiencies are Widespread

A recent study showed that in the over 60s, as calcium and magnesium deficiencies increased, cognitive test scores got worse.⁶

Meanwhile, researchers from the University of South Carolina discovered that only around 60% of women of all ages, and men aged 71 and older, met the estimated average requirement for calcium from both foods and supplements. And in all adults aged over 71, magnesium intake from food averaged only 276 mg, well short of the 320 mg needed by women and 420 needed by men.⁷

Getting these and other minerals from food is less easy these days because of soil depletion, high intakes of fiber that impair their absorption, and phytates, which biochemically lock up minerals in plant fiber, rendering them unusable. For all these reasons, and regardless of the type of water hardness area you live in, supplementing minerals is recommended to protect the brain and overall health.

Summary

A new study reveals that people living in areas with hard water—which contains higher levels of calcium and magnesium—may have a significantly lower risk of Alzheimer’s and vascular dementia. Researchers found that soft water was linked to brain atrophy in 24 regions and up to a 24% increased risk of dementia. Though some experts are skeptical of the study's strength, the broader evidence still highlights how crucial minerals like calcium and magnesium are for brain function. With deficiencies in these nutrients common among older adults, supplementation and diet remain important tools for maintaining cognitive health.

Frequently Asked Questions

• What is hard water? Hard water contains higher levels of dissolved minerals, mainly calcium and magnesium, which it picks up as it flows through soil and rock.
• How does hard water affect the brain? According to a recent study, people living in hard water areas may have a lower risk of Alzheimer’s and vascular dementia, potentially due to higher mineral intake.
• Is soft water bad for brain health? The study suggests an increased risk of brain atrophy and dementia in soft water areas, but experts caution that more research is needed before making broad conclusions.
• Should I supplement calcium and magnesium if I live in a soft water area? Yes. Even in hard water regions, many people don’t get enough of these essential minerals through food or water, making supplementation beneficial.
• Can I rely on food alone for these minerals? It’s becoming more difficult due to soil depletion and absorption inhibitors like phytates in plant-based foods. Supplements can help fill the gap.